This invention relates to a process for the production of synthetic surface coverings. More particularly, this invention relates to a method of making synthetic coverings for floors, walls, etc. which exhibit a cracked appearance. This invention also relates to the products obtained in accordance with this novel process.
Increasingly, in the production of synthetic decorative coverings intended for floors, walls, and the like, attempts have been made to manufacture the coverings using conventional and naturally occurring materials such as ceramics and the like. A particularly decorative effect obtained when using ceramic materials resides in the naturally occuring cracks. However, such a cracked appearance is difficult to obtain with synthetic materials deposited in the form of a coating, for example, on a conventional substrate. Moreover, the attempted reproduction of cracks by printing leads to the problem of precluding an authentic reproduction of the "natural" cracked effect, and the motifs obtained are necessarily repetitive, i.e., without a random nature. Also, printing does not permit depth (relief) to be imparted to the synthetic covering material.
French Specification No. A2,126,658 discloses a known process for applying a covering material in the form of an emulsion in order to produce crazed (cracked) configurations. In this case, a lower synthetic covering material containing a mineral material having a high swelling property is deposited on a substrate. This lower covering material is dried, and a hardened covering material containing a silicon dioxide base is then applied thereon. In the process described in the French specification, the lower covering material absorbs the water contained in the hardened covering material and simultaneously causes both the contraction of the hardened material and the formation of crazed configurations. A disadvantage of this French process resides in the fact that there are two different layers of composition to be applied, which necesitates intermediate drying. This process is therefore time consuming and burdensome.
French Patent document No. A2,247,494 relates to a cracked film of a PVC polymer including at least one plasticizer homogenously distributed therein. French Pat. No. A2,247,494 also discloses a synthetic covering comprised of a conventional substrate covered with the PVC, a polymeric film, as well as a process for the preparation of the latter. This process relies on a two-phase system consisting of (1) polymer-plasticizer and (2) water. However, this process does not permit adequate control of the formation of the cracks or of the size of the cracks. Moreover, this process requires large quantities of water.
U.S. Pat. No. 2,612,456 similarly relates to a process for the production of a decorative and protective covering which exhibits a cracked appearance. This process utilizes an organosol including particles of an organic copolymer of vinyl chloride and vinyl acetate, said particles being dispersed in a volatile organic liquid. The organic liquid must have a swelling effect on particles of polymer. As in the above-discussed process, this process is also difficult to control making it quite difficult to obtain a dense network of cracks. Moreover, this process like-wise requires large quantities of solvent.
Accordingly, an object of the present invention is to provide a process for the production of synthetic coverings (i.e. for floors or walls), which exhibit a cracked appearance and which requires only a single layer of synthetic material to obtain the cracked effect.
Another object of the present invention is to provide a process for the production of synthetic coverings having a cracked appearance in which the required quantities of solvent or of water are substantially reduced as compared with the prior art.
Another object of the present invention is to provide a process for the production of synthetic coverings including cracks with depth, that is, relief being provided substantially throughout the mass of at least one layer of the covering.
Yet another object of the present invention is to provide a synthetic covering for floors, walls and the like which exhibit a cracked appearance having a random nature.